In a medium, non-stick skillet over medium heat, cook chicken until no longer pink and juices run clear. Drain excess fat. Cube the chicken and return it to the skillet. Add the onion, sour cream, Cheddar cheese, parsley, oregano and ground black pepper. Heat until cheese melts. Stir in salt, tomato sauce, water, chili powder, green pepper and garlic.
Roll even amounts of the mixture in the tortillas. Arrange in a 9×13 inch baking dish. Cover with taco sauce and 3/4 cup Cheddar cheese. Bake uncovered in the preheated oven 20 minutes. Cool 10 minutes before serving.